The present invention relates to a device for centering, straightening up and turning the loads of the motorized converyors such as roller conveyors.
When loads such as pallets are conveyed on the motorized roller conveyors it has been found that these pallets are not always on the axis of movement and/or not always centered in relation to the conveyors. This shifting movement is often the result of the fact that the loads are badly arranged on the conveyors at the moment of loading. Even when they are properly arranged on the conveyors, the pallets are progressively diverted during transportion from one station to the next for a multiplicity of reasons. In the majority of cases, the two causes for the load being carried out of its path in a lateral direction (bad positioning at the outset and lateral diversion) are complementary to each other and in practice it follows that the pallets are never suitably centered.
Depending on the nature of their implementation, stacking in the case of corrugated cardboard sheets, and the different stations where they are processed and/or handled, the pallets may be equally arranged on the conveyor at 90.degree. from each other.
Moreover when, at the end of the conveyor circuit, the pallets have to be encircled for example, by means of automatic machines forming an integral part of the conveyors or are given a covering made of a plastics material and pass across a shrinking furnace, it is absolutely essential that the said pallets should arrive at these different stations perfectly centered, i.e. right in the center of the conveyors, at right angles in relation to the conveyor and if necessary directed in a suitable direction. In fact, in the case of rectangular pallets it is necessary that their length should lie in the direction of movement if it is desired that encircling and/or shrinking of the thermoplastic covering should take place under the best conditions.
There already exist means for effecting the above-mentioned functions. For example, it may be a question of a lift which displaces the pallets and/or turns them round by a certain angle in order to bring them into an adequate position. But all the known apparatus are not automatic in this sense in that they do not carry out the different functions automatically and in a repetitive manner from one load to the next while in general positioning is left to the visual appreciation of the operator of the said apparatus.